Ariel Sharon suffered a humbling finish to the most bruising week of his prime minstership yesterday with opinion polls charting a deepening disenchantment with the Israeli leadership.

A poll conducted for the Yedioth Ahronoth newspaper, Israel's largest Hebrew daily, showed that 61% of Israelis were dissatisfied with Mr Sharon's performance, and just 38% would give him a passing grade for his handling of the 17-month Palestinian uprising.

His credibility score fell to 54%, a staggering drop from his approval rating of 70% in December and 77% last July.

The collapse of Mr Sharon's credibility - accelerated by high Israeli casualties during a wave of Palestinian attacks on military targets and Jewish settlements in the West Bank - is unlikely to be arrested by his poor performance during a nationally televised address on Thursday.

Amid continued attacks on Israelis in the West Bank yesterday, Israeli commentators showed the prime minister no mercy, saying he had utterly failed to calm his people's anxieties on security, or Israel's deepening economic recession.

"The lion that meowed," said the headline on the front page comment in Ha'aretz newspaper, which went on to cavil: "With speeches like these to the nation, it is doubtful whether England would have emerged whole from world war two, or whether the United States would have dragged itself out of the economic crash of 1929."

The piece concluded: "The prime minister spoke last night in lofty words, but did not give the concerned citizen any horizon or any hope to cling to and shake off the despair."

There was little credit given to Mr Sharon's plan to establish buffer zones between the West Bank and Israel.

Although the prime minister gave no details of the separation zone, and refused to say how it would effect some 145 Jewish settlements in the occupied territories, Israeli radio yesterday described a plan to create a 125-mile security cordon along the borders of the West Bank. It said the army would begin mapping out the zone in the coming weeks, imposing concrete barriers and eventually a fence.

Political sources told Israeli Radio that the zone, which would be miles deep in places, would be set off with trenches and minefields, in effect creating a death strip for Palestinians. However, aides for the prime minister did not mention land mines, and said the army would patrol the zone, which would be demarcated by roadblocks and high voltage fences.

The notion of a buffer zone between the West Bank and Israel has been in circulation for years. Similar barricades were imposed on a stretch of the West Bank last summer, cutting off the Palestinian city of Tulkaram from the Israeli suburb of Bat Hefer with razor wire, electric fences and a three-metre high wall.

Although yesterday brought a lull in Israel's bombardment of Palestinian towns, and security officials on both sides resumed contacts after several weeks, there was no let-up in the attacks by Palestinian militants.

An Israeli motorist was shot dead north of Jerusalem and a suicide bomber struck the supermarket of an illegal Jewish settlement at Efrat. A customer in the shop shot and killed the bomber before he could fully detonate his explosive belt.

Near the West Bank city of Hebron, a Jewish settler who shot and wounded two Palestinians was mistakingly wounded by Israeli soldiers.

The thwarted bombing at Efrat, south of Jerusalem, marked the second time in less than a week that a Palestinian militant has succeeded in penetrating the heavily guarded Jewish settlements.

The attack underscored the vulnerability of the isolated Jewish outposts, despite Israel's suffocating blockade of Palestinian towns. Yesterday, the Israeli army closed off the main road to Ramallah, preventing Palestinians from visiting their relatives for the feast of Eid al-Adha.